Torque is produced in an induction motor through the interaction of magnetic fields and electric currents. Induction motors are a type of AC (alternating current) motor, and they work based on electromagnetic principles.
Here's a simplified explanation of how torque is produced in an induction motor:
Stator: The stator is the stationary part of the motor and consists of a set of windings or coils that are connected to the AC power supply. When AC voltage is applied to these windings, it creates a rotating magnetic field in the stator.
Rotor: The rotor is the rotating part of the motor and is typically made up of conductive bars or coils. The rotor is placed within the stator's magnetic field.
Induction: When the AC voltage is applied to the stator windings, it generates a constantly changing magnetic field that cuts across the rotor conductors. This changing magnetic field induces a voltage in the rotor conductors, according to Faraday's law of electromagnetic induction.
Eddy Currents: The induced voltage in the rotor conductors causes electric currents to flow through them. These currents are known as "eddy currents."
Interaction: The rotor conductors carrying eddy currents also create their own magnetic field. This rotor magnetic field interacts with the stator magnetic field, causing a force to be exerted on the rotor.
Torque Generation: The interaction between the stator and rotor magnetic fields creates a torque on the rotor, causing it to start rotating. The direction of rotation is such that the rotor tries to follow the rotating magnetic field of the stator.
Slip: The rotor never quite catches up with the speed of the rotating magnetic field due to a phenomenon called "slip." This slip allows a relative motion between the rotor and the stator field, which maintains the production of torque and keeps the motor running.
It's important to note that this explanation provides a simplified overview of how torque is produced in an induction motor. The actual physics and engineering principles involved are more complex, including factors such as the number of poles in the motor, the design of the stator and rotor, the motor's load, and the efficiency of the motor. Nonetheless, the interaction of the changing magnetic fields, induced currents, and resulting torque is fundamental to the operation of induction motors.